The present invention relates generally to the field of filtration assemblies. In its more preferred forms, the present invention relates to multiple tubular filter cartridges having pleated filter media, whereby the filter cartridges are held together collectively as a unit (xe2x80x9ccagedxe2x80x9d) in parallel relationship to one another between spaced-apart end plates, and to the filtration systems which employ the same.
Caged filter cartridge assemblies are known and have been employed conventionally in fluid-filtration assemblies. Conventional caged filter assemblies typically include an array comprised of a large number (e.g., eighteen) of generally tubular filter cartridges positioned parallel to one another between a pair of spaced-apart end plates. A tie rod extends generally centrally of the filter cartridge array and structurally unites the spaced-apart end plates to form an integral unit.
Recently, in U.S. Pat. No. 6,495,037 (hereinafter xe2x80x9cthe ""037 patentxe2x80x9d), novel caged filter cartridge assemblies are disclosed whereby the structural integrity of the assemblies is improved. More specifically, the invention described in the ""037 patent is embodied in tie rod-less caged filter cartridge assemblies wherein the structural integrity of the assembly is provided solely by means of the individual filter cartridges. That is, the end plates of the filter cartridge assembly are provided with plural seat recesses each adapted to receive an end portion of a respective filter cartridge. An annular lock ring is associated with each seat recess so as to immovably lock the filter cartridge ends therewithin. In such a manner, each of the individual filter cartridges serves to structurally unite the opposed spaced-apart end plates one to another in the absence of a tie rod so that the collective torsional and longitudinal rigidity of the assembly is significantly enhanced as compared to conventional tie rod assemblies.
As may be appreciated, the caged filter cartridge assemblies disclosed in the ""037 patent are especially adapted to be employed with melt-blown filter media (i.e., so as to achieve the desired fluid sealing effect between the annular lock ring and the filter media. Thus, the structural integrity of the caged filter cartridges and the sealing effect provided by the annular lock ring may not be evident when pleated filter media is employed. It would therefore be highly desirable if filter cartridge assemblies having pleated filter media could be used with the end plates as disclosed in the ""037 patent. It is towards fulfilling such a need that the present invention is directed.
Broadly, therefore, the present invention relates to caged filter cartridge assemblies which include filter cartridges provided with pleated filtration media. More specifically, in accordance with the present invention, caged filter cartridge assemblies are provided which have a pair of coaxially spaced-apart end plates, and a number of tubular filter cartridges extending between said end plates. These end plates include seat recesses having a coaxially disposed retaining ring establishing an annular terminal lock edge. The filter cartridges include end caps at each opposed end thereof which are received within respective ones of said seat recesses. The end caps have at least one annular lock ring which is forcibly engaged with the terminal annular lock edge of the retaining ring so as to join the end cap, and thus said filter cartridge, to the end plates.
These and other aspects and advantages will become more apparent after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.